Exploring the future adult vaccine landscape—crowded schedules and new dynamics

Amidst the backdrop of the COVID-19 pandemic, vaccine innovation has garnered significant attention, but this field was already on the cusp of a groundbreaking renaissance. Propelling these advancements are scientific and technological breakthroughs, alongside a growing understanding of the societal and economic boons vaccines offer, particularly for non-pediatric populations like adults and the immunocompromised. In a departure from previous decades where vaccine launches could be seamlessly integrated into existing processes, we anticipate potentially than 100 novel, risk-adjusted product launches over the next 10 years in the adult vaccine market, primarily addressing new indications. However, this segment is infamous for its challenges: low uptake, funding shortfalls, and operational hurdles linked to delivery and administration. To unlock the societal benefits of this burgeoning expansion, we need to adopt a fresh perspective to steer through the dynamics sparked by the rapid growth of the global adult vaccine market. This article aims to provide that fresh perspective, offering a detailed analysis of the anticipated number of adult vaccine approvals by category and exploring how our understanding of barriers to adult vaccine uptake might evolve. We incorporated pertinent insights from external stakeholder interviews, spotlighting shifting preferences, perceptions, priorities, and decision-making criteria. Consequently, this article aspires to serve as a pivotal starting point for industry participants, equipping them with the knowledge to skillfully navigate the anticipated surge in both volume and complexity.

Our research methodology was built on an iterative, sequential primary market research design using mixed methods.This encompassed a five-step process that began with fact gathering and hypothesis identification.The initial fact-gathering stage involved an extensive exploration of existing knowledge, data, and available information on the potential evolution of the adult vaccine landscape.This investigation covered publications, clinical trials, and product pipelines to establish a solid foundation for the research.Hypotheses on potential future market state scenarios were developed based on the results of the fact-finding stage.The study then proceeded with targeted qualitative interviews with key stakeholders across the value chain, designed to refine U.S. hypotheses, followed by quantitative surveys with U.S. Vaccine Purchasers, Immunizers and Consumers designed to characterize degree of impact and tradeoffs for U.S. future state scenarios.

Participants and Recruitment
For the qualitative interviews, we engaged with 53 U.S. stakeholders who filled various roles within the value chain.These included former ACIP members and policy makers, payers, selfinsured employers, key opinion leaders (KOLs) who do not immunize, retail pharmacy purchasers, integrated delivery network (IDN) purchasers, group purchasing organizations (GPOs), wholesaler/distributors, immunizing healthcare providers (HCPs) including pharmacists, primary care physicians (PCPs), physician assistants (PAs), and patient advocacy groups (PAGs).
In addition, the study involved 683 stakeholders who participated in the quantitative survey.These were composed of stocking & purchasing stakeholders (n=80), immunizers (n=103), and consumers (n=500) selected based on specific demographic and health criteria.

Discussion Guide
During the qualitative interviews, we presented various stimuli to the participants to facilitate conversation.These included showcards that illustrated the evolution of the adult vaccine landscape across disease states over time, highlighted current and future disease targets and vaccines, and depicted the current and potential future ACIP recommendations.Additionally, we presented two future scenarios for the development of the adult vaccines market.The first scenario was optimistic, showing a future where stakeholders adapt and seize new opportunities, while the second scenario was pessimistic, illustrating a future where stakeholders maintain their usual practices that might not fit the evolving market.
First, current eligible populations, by disease indication, were determined using U.S. census data from 2021.A US population compound annual growth rate (CAGR) of 1.6% was applied to estimate the US population in 2023.Populations were segmented by age group for each disease indication, which were determined using the ACIP recommendations.For indications where recommendations for at-risk populations existed, at-risk-rates were determined (Supplementary Table 1) and total at-risk populations were included within the eligible population.Projected eligible populations from 2024 through 2032 were calculated assuming a CAGR of 1.6%.The 2032 coverage rate for each vaccine indication was estimated using the following assumptions:
• Pneumococcal: Stable but expected to overcome pandemic spillover effect by ten yearssteady growth until then.• Hep-B, Meningococcal, HPV: Minimal growth in coverage anticipated.
• Zoster: Room for further penetration with additional launches.
• CMV: Expected to follow similar trajectory to other routine vaccines.
• Tdap, Hep-A: No growth anticipated.Coverage rates over time from years 2024 through 2031 (Supplementary Table 3) were calculated using the following equation: where x = year.

Table 1 .
At-Risk rates and population statistics and assumptions.

Table 2 .
Current Coverage Rates

Table 3. Coverage Rate over Time Vaccine Type Indication 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032
were taken into account when determining what year coverage begins.The total dose volume per year (Supplementary Table4) was calculated for each vaccine indication by multiplying the newly covered populations per year by the number of doses in each vaccine's regimen.This dose number was determined using the ACIP recommendations.

Table 4 .
Covered Doses per Year